Sahih Bukhari
Wedlock, Marriage (Nikaah)
Volume: 007 / Book Number: 062 / Hadith Number: 78
Narrated Anas:
Abdur Rahman bin 'Auf married a woman and gave her gold equal to the weight of a date stone (as Mahr). When the Prophet noticed the signs of cheerfulness of the marriage (on his face) and asked him about it, he said, "I have married a woman and gave (her) gold equal to a date stone in weight (as Mahr)."